package programmercarl.动态规划.C9;

class Solution1 {
    public static int numTrees(int n) {
        int[] dp = new int[n + 1];//初始化为n还是n+1要看0是否有实际意义
        dp[0] = 1;
        dp[1] = 1;
        for (int i = 2; i <= n; i++) {
            for (int j = 1; j <= i; j++) {
                dp[i] += dp[j - 1] * dp[i - j];
            }
        }
        return dp[n];
    }

    public static void main(String[] args) {
        int val = numTrees(2);
        System.out.printf(String.valueOf(val));
    }
}